Add welcome page for test explorer in LightWeight mode (#1046)

Author: jdneo

package.json

@@ -70,6 +70,13 @@
                 }
             ]
         },
+        "viewsWelcome": [
+            {
+              "view": "testExplorer",
+              "contents": "No test cases are listed because the Java Language Server is currently running in [LightWeight Mode](https://aka.ms/vscode-java-lightweight). To show test cases, click on the button to switch to Standard Mode.\n[Switch to Standard Mode](command:java.server.mode.switch?%5B%22Standard%22,true%5D)",
+              "when": "java:serverMode == LightWeight"
+            }
+        ],
         "menus": {
             "view/title": [
                 {

src/constants/commands.ts

@@ -3,7 +3,6 @@
 
 export namespace JavaLanguageServerCommands {
     export const EXECUTE_WORKSPACE_COMMAND: string = 'java.execute.workspaceCommand';
-    export const SWITCH_SERVER_MODE: string = 'java.server.mode.switch';
 }
 
 export namespace JavaTestRunnerDelegateCommands {
@@ -30,5 +29,4 @@ export namespace JavaTestRunnerCommands {
     export const RELAUNCH_TESTS: string = 'java.test.relaunch';
     export const JAVA_TEST_CANCEL: string = 'java.test.cancel';
     export const JAVA_CONFIG_MIGRATE: string = 'java.test.config.migrate';
-    export const JAVA_TEST_SWITCH_SERVER_MODE: string = 'java.test.switch.server.mode';
 }

src/explorer/testExplorer.ts

@@ -4,14 +4,13 @@
 import * as path from 'path';
 import { Command, Disposable, Event, EventEmitter, ExtensionContext, extensions, Range, ThemeIcon, TreeDataProvider, TreeItem, TreeItemCollapsibleState, Uri, workspace, WorkspaceFolder } from 'vscode';
 import { JavaTestRunnerCommands } from '../constants/commands';
-import { isStandardServerReady, isSwitchingServer } from '../extension';
+import { isLightWeightMode, isSwitchingServer } from '../extension';
 import { ITestItem, TestKind, TestLevel } from '../protocols';
 import { ITestResult, TestStatus } from '../runners/models';
 import { testFileWatcher } from '../testFileWatcher';
 import { testItemModel } from '../testItemModel';
 import { testResultManager } from '../testResultManager';
 
-const LIGHTWEIGHT_NODE_ID: string = ':LIGHTWEIGHT_MODE:';
 export class TestExplorer implements TreeDataProvider<ITestItem>, Disposable {
     public readonly testExplorerViewId: string = 'testExplorer';
 
@@ -26,20 +25,6 @@ export class TestExplorer implements TreeDataProvider<ITestItem>, Disposable {
     }
 
     public getTreeItem(element: ITestItem): TreeItem | Thenable<TreeItem> {
-        if (element.id === LIGHTWEIGHT_NODE_ID) {
-            return {
-                label: element.displayName,
-                collapsibleState: TreeItemCollapsibleState.None,
-                command: {
-                    command: JavaTestRunnerCommands.JAVA_TEST_SWITCH_SERVER_MODE,
-                    title: 'Switch to Standard mode',
-                },
-                contextValue: 'UNTESTABLE_NODE',
-                tooltip: 'Switch the Java Language Server to Standard mode to show all the test cases',
-                iconPath: new ThemeIcon('info'),
-            };
-        }
-
         return {
             label: element.displayName,
             collapsibleState: this.resolveCollapsibleState(element),
@@ -50,28 +35,15 @@ export class TestExplorer implements TreeDataProvider<ITestItem>, Disposable {
     }
 
     public async getChildren(element?: ITestItem): Promise<ITestItem[]> {
+        if (isLightWeightMode()) {
+            return [];
+        }
         if (isSwitchingServer()) {
             await new Promise<void>((resolve: () => void): void => {
                 extensions.getExtension('redhat.java')!.exports.onDidServerModeChange(resolve);
             });
         }
-        if (!isStandardServerReady()) {
-            return [
-                {
-                    id: LIGHTWEIGHT_NODE_ID,
-                    displayName: 'Click to load test cases...',
-                    fullName: LIGHTWEIGHT_NODE_ID,
-                    kind: TestKind.None,
-                    project: '',
-                    level: TestLevel.Folder,
-                    location: {
-                        uri: '',
-                        range: new Range(0, 0, 0, 0),
-                    },
-                    children: undefined,
-                },
-            ];
-        }
+
         let nodes: ITestItem[] = [];
         if (!element) {
             nodes = this.getWorkspaceFolders();

src/extension.ts

@@ -4,13 +4,13 @@
 import * as fse from 'fs-extra';
 import * as os from 'os';
 import * as path from 'path';
-import { commands, DebugConfiguration, Event, Extension, ExtensionContext, extensions, Range, Uri, window } from 'vscode';
+import { DebugConfiguration, Event, Extension, ExtensionContext, extensions, Range, Uri, window } from 'vscode';
 import { dispose as disposeTelemetryWrapper, initializeFromJsonFile, instrumentOperation, instrumentOperationAsVsCodeCommand } from 'vscode-extension-telemetry-wrapper';
 import { testCodeLensController } from './codelens/TestCodeLensController';
 import { debugTestsFromExplorer, openTextDocument, runTestsFromExplorer } from './commands/explorerCommands';
 import { openLogFile, showOutputChannel } from './commands/logCommands';
 import { runFromCodeLens } from './commands/runFromCodeLens';
-import { JavaLanguageServerCommands, JavaTestRunnerCommands } from './constants/commands';
+import { JavaTestRunnerCommands } from './constants/commands';
 import { testExplorer } from './explorer/testExplorer';
 import { logger } from './logger/logger';
 import { ITestItem } from './protocols';
@@ -100,12 +100,6 @@ async function doActivate(_operationId: string, context: ExtensionContext): Prom
         instrumentOperationAsVsCodeCommand(JavaTestRunnerCommands.OPEN_TEST_LOG, async () => await openLogFile(storagePath)),
         instrumentOperationAsVsCodeCommand(JavaTestRunnerCommands.JAVA_TEST_CANCEL, async () => await runnerScheduler.cleanUp(true /* isCancel */)),
         instrumentOperationAsVsCodeCommand(JavaTestRunnerCommands.JAVA_CONFIG_MIGRATE, async () => await migrateTestConfig()),
-        instrumentOperationAsVsCodeCommand(JavaTestRunnerCommands.JAVA_TEST_SWITCH_SERVER_MODE, async () => {
-            if (isSwitchingServer()) {
-                return;
-            }
-            await commands.executeCommand(JavaLanguageServerCommands.SWITCH_SERVER_MODE);
-        }),
     );
 }
 
@@ -115,15 +109,25 @@ export function isStandardServerReady(): boolean {
         return true;
     }
 
-    if (serverMode !== 'Standard') {
+    if (serverMode !== LanguageServerMode.Standard) {
         return false;
     }
 
     return true;
 }
 
+export function isLightWeightMode(): boolean {
+    return serverMode === LanguageServerMode.LightWeight;
+}
+
 export function isSwitchingServer(): boolean {
-    return serverMode === 'Hybrid';
+    return serverMode === LanguageServerMode.Hybrid;
 }
 
 let serverMode: string | undefined;
+
+const enum LanguageServerMode {
+    LightWeight = 'LightWeight',
+    Standard = 'Standard',
+    Hybrid = 'Hybrid',
+}